THIS AVALANCHE ADVISORY EXPIRED ON January 12, 2015 @ 7:31 am
Avalanche Advisory published on January 11, 2015 @ 7:31 am
Issued by Andy Anderson - Tahoe National Forest

LOW avalanche danger exists on all elevations and aspects. If the cloud cover arrives later than forecasted or temperatures remain warmer than forecasted, some minor wet snow instabilities may form. Continue to practice safe travel habits and thoughtful decision making when traveling in the backcountry.

1. Low

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Above Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

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Near Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

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Below Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
    Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
Avalanche Problem 1: Loose Wet
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  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Less overnight cloud cover and cooler nighttime temperatures should have allowed a decent overnight refreeze. This refreeze combined with today's increased cloud cover, cooler temperatures, and increased winds should cause significant wet snow instabilities to remain unlikely. If the cloud cover arrives later than forecasted or temperatures remain warmer than forecasted, some minor wet snow instabilities like small roller balls, pinwheels, or small wet snow sluffs may occur on sun-exposed slopes or mid to lower elevation northerly aspects where the surface snow has not experienced many melt-freeze cycles.

recent observations

Yesterday wet snow existed on all aspects up to 9000 ft. on Andesite Ridge, Incline Lake Peak, and Elephant's Back. In some places in these areas, several inches of wet snow existed on top of a supportable melt-freeze crust and in others especially around exposed rocks and trees wet snow existed to the ground. Above 9000 ft on Incline Lake Peak, a firm cold snow surface consisting of wind crusts, scoured surfaces, and small isolated patches of soft snow existed on the northerly aspects. On the sun-exposed southerly aspects above 9000 ft on Incline Lake Peak, about 1 inch of soft wet surface snow formed above a supportable melt freeze crust by midday.

Snowpit data from these three areas and in the Bear Valley area showed the that formation of a weak layer below the uppermost rain crust has slowed down due to the warmer temperatures and warmer snowpack. Tests on this layer indicated that if it does break the resulting fractures are not likely to travel very far along the layer. 

Weather and CURRENT CONDITIONS
weather summary

The forecast calls for decreasing temperatures, increased cloud cover, and some isolated snow showers and flurries today as a result of a low pressure system over southern CA. The west and southwest winds should start to increase this afternoon as a cold front moves into the region from the north. This cold front will bring cooler temperatures, continued cloud cover, and slight chance for light snow showers through Monday. Snow levels should remain between 6000 and 6500 ft. Since very little moisture accompanies these systems, the snow showers should not produce any accumulation if they occur. 

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 29 to 36 deg. F.
Max. temperature in the last 24 hours: 39 to 45 deg. F.
Average wind direction during the last 24 hours: West to southwest
Average wind speed during the last 24 hours: 10 mph
Maximum wind gust in the last 24 hours: 28 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 24 to 34 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Sunday Sunday Night Monday
Weather: Mostly cloudy with isolated flurries in the morning and isolated snow showers in the afternoon. Mostly cloudy with isolated snow showers. Cloudy becoming mostly cloudy with a slight chance of snow showers.
Temperatures: 33 to 40 deg. F. 22 to 29 deg. F. 29 to 36 deg. F.
Wind Direction: Southwest West West
Wind Speed: 0 to 5 mph increasing to 10 to 15 mph with gusts to 25 mph in the afternoon 10 to 15 mph with gusts to 25 mph 15 to 20 mph with gusts to 30 mph in the morning becoming light in the afternoon
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Sunday Sunday Night Monday
Weather: Mostly cloudy with isolated flurries in the morning and isolated snow showers in the afternoon. Mostly cloudy with isolated snow showers. Cloudy becoming mostly cloudy with a slight chance of snow showers.
Temperatures: 29 to 36 deg. F. 20 to 27 deg. F. 25 to 32 deg. F.
Wind Direction: West West West shifting to the north in the afternoon
Wind Speed: 0 to 10 mph increasing to 25 to 30 mph with gusts to 40 mph in the afternoon 20 to 30 mph with gusts to 40 mph 25 to 30 mph with gusts to 40 mph decreasing to 15 to 20 mph with gusts to 30 mph in the afternoon
Expected snowfall: 0 in. 0 in. 0 in.
Disclaimer

This avalanche advisory is provided through a partnership between the Tahoe National Forest and the Sierra Avalanche Center. This advisory covers the Central Sierra Nevada Mountains between Yuba Pass on the north and Ebbetts Pass on the south. Click here for a map of the forecast area. This advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.